Grassy Woodlands Restoration Project

Grassland seed head

Native grass in full seed.

The critically endangered grasslands on Hobart's Queens Domain were once widespread across Tasmania, but today are limited to small fragments north of Hobart and into the Midlands, where they face complex and constant threats. 

Development, weeds, climate change and altered fire regimes have all taken a toll on grassland and grassy woodland ecosystems across Tasmania, but a joint effort by the City of Hobart and the University of Tasmania’s Professor Jamie Kirkpatrick is restoring these ecosystems on the Queens Domain.

Encroachment of sheoaks

The Queens Domain has seen dramatic landscape changes over the years. The removal of traditional fire management, followed by land clearing practices and poor land management techniques paved the way for weeds, shrubs and small trees to begin their slow march across the grassland. 

Without regular burning, slashing or grazing, shrubby seedlings shaded out the native kangaroo grass (Themeda triandra) and pushed out inter-tussock species like native orchids, daisies, lilies and twining pea flowers. 

Drooping sheoak (Allocasuarina verticillata) gradually closed in on the grasslands, changing their structure to form a dense canopy with little else underneath.

Although naturally occurring on the Domain, sheoaks can quickly grow out of control. The fallen sheoak branchlets form a dense mat that prevents undergrowth from developing. 

In the 1930s and 40s, there was a brief reprieve from the Allocasuarina invasion when large stands were sawn down and hauled out to fire up the ovens of bakers in town. Within a couple of decades, however, the Queens Domain was largely dominated by this species. 

UTAS study

The dramatic change to vegetation structure on the Queens Domain has been the subject of a long-term study by UTAS Professor Jamie Kirkpatrick. Documenting vegetation change in the Domain’s grassy woodlands since 1974, Professor Kirkpatrick’s remarkable research has guided restoration efforts on the Domain for decades. 

His documentation showed sites of high conservation value within the grasslands were markedly declining as sheoaks advanced.

Creating room for rare species

One of the major problems in maintaining rare plant species on the Domain is that most of them do not like thick litter from sheoaks or competition from kangaroo grass, so are now surviving under exotic cypresses. 

The Soldiers Memorial Avenue holds some of the Domain’s rarest remnant species. It was understood in the early 90s that the City of Hobart’s fire regime would need to be frequent and regular to suppress the spread across the rest of the reserve.

Mature sheoaks and their dense carpet of needles can make it difficult for a planned burn to effectively manage the encroaching woody vegetation and larger trees were surviving the burns unscathed – burning alone is not enough to progress the Domain’s restoration.

An integrated approach

The City of Hobart’s current integrated approach of mechanical thinning and periodic burning has made significant headway in the ecological restoration of the grassy woodlands on the Queens Domain. 

The City’s Fire and Biodiversity Team and Bushcare volunteer crews have been working hard to keep sheoak numbers in check.

By freeing up space around the white gum (Eucalyptus viminalis) and blue gum (Eucalyptus globulus) saplings surviving among the sheoaks, these young trees will have enough space, light and nutrient to put on growth and become resilient canopy trees. 

It takes approximately 100 years for a tree to begin forming hollows, so these saplings will one day create critical habitat for swift parrots, pardalotes, masked owls and other hollow-nesting species.

Where sheoaks have been removed, the lowland grasslands have been quick to return. According to Professor Kirkpatrick from the University of Tasmania, “the wallabies and pademelons now on the Domain are also doing their bit, while the bandicoots create regeneration niches”. 

A walk along the Joggers Loop today will take you past elbow-high speargrasses where thick sheoak once stood. The grasslands’ purple and yellow wildflower palette is gradually coming back – Dianella lilies and delicate button flowers dot the grassy understorey.

Grasslands have evolved alongside people with complex management regimes, and caring for them in the face of a changing climate will be no easy task. The City of Hobart’s longest-running ecological restoration project is far from over.

How to help

Volunteers with the City of Hobart’s Bushcare program are playing an important role in restoring and caring for the native grassy woodlands on the Queens Domain by helping to remove sheoak seedlings and keeping out other invasive weeds.

The best way you can help care for Hobart’s native grasslands is by joining our Bushcare program and actively participating in Bushcare working bees on the Queens Domain with the Cornelian Bay Bushcare group. 


Native grasslands gallery